Adsorción de Hg y Cu por cáscara de Solanum tuberosum L. en agua de relave de la minería de la localidad de Secocha – Camaná – Arequipa

Con la finalidad de amortiguar la contaminación causada por la minería y los metales que estos desechan a las cuencas y fuentes de agua, se investigó, la capacidad de biosorción de cobre y mercurio por cáscara de papa (Solanum tuberosum), se tomaron dos tipos de muestras una usando diluciones patrón en el laboratorio y la otra tomada del agua de relave minero de Secocha – Camaná – Arequipa; para la primera se realizaron tres tratamientos con cáscara de Solanum tuberosum con tratamiento de NaOH (adsorbente activado) previo y tres sin tratamiento químico (adsorbente sin activar); para ambos se tomaron en cuenta tres variables (pH, concentración de metal en ppm y peso del biosorbente) para identificar las variables optimas, por lo cual para Cu2+ se realizaron los tratamientos a 5, 6, 7, 8 y 9 de pH; 5,10,20,30,40 y 50 de concentración de Cu2+ (ppm), y 1,3,5,8,10g del adsorbente, resultando que la cáscara de Solanum tuberosum a un pH neutro, una concentración de Cu2+ de 50ppm, presenta el porcentaje de remoción y la capacidad de adsorción más alta, en cuanto al peso del bioadsorbente la mejor capacidad de adsorción es con cáscara sin activar a 1 g, el cual difiere con la cáscara activada debido a que esta presenta el mayor porcentaje de remoción utilizando el método de absorción atómica como método de lectura para el metal Cu2+. Los tratamientos para Hg2+ fueron, en número, los mismos, con variaciones en las variables, considerando un pH de 5, 7 y 9; a concentración de mercurio de 5, 8 y 10 (ppm) y 1, 5 y 10g del bioadsorbente, obteniendo que, la cáscara de Solanum tuberosum activada a un pH ácido de 5 y una concentración de Hg2+ del 10ppm, presenta un porcentaje de remoción y capacidad de adsorción más alto, y en cuanto al peso si hay una diferencia significativa en el adsorbente activado y sin activar, observando que el peso del adsorbente es proporcionalmente inverso a la capacidad de adsorción, es decir que para cáscara activada a 1 gramo de biosorbente presenta la mayor capacidad de adsorción y a 10 gramos el mayor porcentaje de remoción. Por otro lado para el segundo tipo de muestra, se realizó un tratamiento por metal, con 3 repeticiones, usando el bioadsorbente (cáscara de Solanum tuberosum) activado y utilizando para este un tratamiento con ditizona y el equipo de espectrofotometría para las mediciones de Hg2+, por lo cual para Cu2+ se obtuvieron datos de la concentración inicial y final, mediante adsorción atómica, resultando 1ppm y 0ppm de concentración de cobre respectivamente según el análisis estadístico ANOVA, por otro lado para Hg2+ se utilizó el mismo adsorbente en mención, usando el método de la ditizona, cuantificando 115ppm antes del tratamiento con el adsorbente activado y 59.67ppm despúes del tratamiento según el mismo análisis estadístico que Cu2+. Por todo esto, la cáscara de Solanum tuberosum adsorbió un 100% de Cu y un 48% de Hg2+. De esta manera se demuestra que la cáscara de Solanum tuberosum activado y no activado es capaz de adsorber metales como Hg2+ y Cu2+ siendo un buen adsorbente destacando entre estos dos el adsorbente activado que puede ser usado en procesos de bioremediación de cuencas contaminadas con metales pesados

Extremely short-length surface plasmon resonance sensors

The impact of the system design on the control of coupling between planar waveguide modes and surface plasmon polaritons (SPP) is analyzed. We examine how the efficiency of the coupling can be enhanced by an appropriate dimensioning of a multi-layer device structure without using additional gratings. We demonstrate that by proper design the length of the device can be dramatically reduced through fabrication a surface plasmon resonance sensor based on the SPP-photon transformation rather then on SPP dissipation

Ultrafast nano-focusing with full optical waveform control

The spatial confinement and temporal control of an optical excitation on nanometer length scales and femtosecond time scales has been a long-standing challenge in optics. It would provide spectroscopic access to the elementary optical excitations in matter on their natural length and time scales and enable applications from ultrafast nano-opto-electronics to single molecule quantum coherent control. Previous approaches have largely focused on using surface plasmon polariton (SPP) resonant nanostructures or SPP waveguides to generate nanometer localized excitations. However, these implementations generally suffer from mode mismatch between the far-field propagating light and the near-field confinement. In addition, the spatial localization in itself may depend on the spectral phase and amplitude of the driving laser pulse thus limiting the degrees of freedom available to independently control the nano-optical waveform. Here we utilize femtosecond broadband SPP coupling, by laterally chirped fan gratings, onto the shaft of a monolithic noble metal tip, leading to adiabatic SPP compression and localization at the tip apex. In combination with spectral pulse shaping with feedback on the intrinsic nonlinear response of the tip apex, we demonstrate the continuous micro- to nano-scale self-similar mode matched transformation of the propagating femtosecond SPP field into a 20 nm spatially and 16 fs temporally confined light pulse at the tip apex. Furthermore, with the essentially wavelength and phase independent 3D focusing mechanism we show the generation of arbitrary optical waveforms nanofocused at the tip. This unique femtosecond nano-torch with high nano-scale power delivery in free space and full spectral and temporal control opens the door for the extension of the powerful nonlinear and ultrafast vibrational and electronic spectroscopies to the nanoscale.Comment: Contains manuscript with 4 figures as well as supplementary material with 2 figure

Treatment of solid organ transplant recipients with autologous Epstein Barr virus–specific cytotoxic T lymphocytes (CTLs)

We have investigated the in vivo safety, efficacy, and persistence of autologous Epstein Barr virus (EBV)–specific cytotoxic T lymphocytes (CTLs) for the treatment of solid organ transplant (SOT) recipients at high risk for EBV-associated posttransplantation lymphoproliferative disease (PTLD). EBV-CTLs generated from 35 patients expanded with normal kinetics contained both CD8 and CD4 lymphocytes and produced significant specific killing of autologous EBV-transformed B lymphoblastoid cell lines (LCLs). Twelve SOT recipients at high risk for PTLD, or with active disease, received autologous CTL infusions without toxicity. Real-time polymerase chain reaction (PCR) monitoring of EBV-DNA showed a transient increase in plasma EBV-DNA suggestive of lysis of EBV-infected cells, although there was no consistent decrease in virus load in peripheral-blood mononuclear cells. Interferon-γ enzyme-linked immunospot (ELISPOT) assay and tetramer analysis showed an increase in the frequency of EBV-responsive T cells, which returned to preinfusion levels after 2 to 6 months. None of the treated patients developed PTLD. One patient with liver PTLD showed a complete response, and one with ocular disease has had a partial response stable for over one year. These data are consistent with an expansion and persistence of adoptively transferred EBV-CTLs that is limited in the presence of continued immunosuppression but that nonetheless produces clinically useful antiviral activity

Maximizing energy coupling to complex plasmonic devices by injecting light into eigenchannels

Abstract Surface plasmon polaritons have attracted broad attention in the optoelectronics field due to their ability to merge nanoscale electronics with high-speed optical communication. As the complexity of optoelectronic devices increases to meet various needs, this integration has been hampered by the low coupling efficiency of light to plasmonic modes. Here we present a method to maximize the coupling of far-field optical waves to plasmonic waves for arbitrarily complex devices. The method consists of experimentally identifying the eigenchannels of a given nanostructure and shaping the wavefront of incident light to a particular eigenchannel that maximizes the generation of plasmonic waves. Our proposed approach increases the coupling efficiency almost four-fold with respect to the uncontrolled input. Our study will help to facilitate the integration of electronics and photonics